The present invention is directed to an apparatus of the type wherein an operating parameter is effective with a value for the duration of an activation phase in a plurality of activation phases following one at time intervals, wherein the value of the operating parameter, the length of the time intervals or the duration of the activation phases, is pre-selectable via a control unit has a display means for the operating parameter and enable means, wherein the operating parameter takes effect in the pre-selected way actuation of the enable means.
Given such an apparatus, the value of the operating parameter for the individual activation phases, the length of the time intervals between successive activation phases and the duration of the individual activation phases can be displayed at the display means, for example in the form of a table, in order to provide an operator with an opportunity to check the pre-selected settings before actuation of the enable means. However, this check becomes difficult and time-consuming as soon as a greater number of activation phases is provided.
The invention is based on the object of specifying an apparatus of the species initially cited wherein it is possible for an operator to quickly and simply check the pre-selected values.
This object is inventively achieved by an apparatus with an operating parameter that is effective with a value for the duration of an activation phase in a plurality of activation phases following one at time intervals, whereby at least the value of the operating parameter, the length of the time intervals or the duration of the activation phases is pre-selectable via a control unit, and the control unit comprises a display means for the operating parameter and enable means, whereby the display means displays the value with which the operating parameter is effective during an activation phase via a time axis in the form of rectangles, whereby the value of the operating parameter is entered at a right angle to the time axis, the length of the rectangles in the direction of the time axis corresponds to the duration of the respective activation phase and the spacings of the edges of successive rectangles indicating the end and the beginning of a time duration from one another represent the time intervals, and whereby the operating parameter can only take effect in the pre-selected way upon actuation of the enable means.
In the case of the invention, thus, the pre-selected values of the operating parameter are two-dimensionally and simultaneously displayed in the time sequence in which they are to take effect, so that a surveyable presentation derives that makes it easy for an operator to check the pre-selected values before actuation of the enable means. The inventive apparatus thereby makes use of the fact that the human eye can perceive graphic objects far faster than it can read characters. As particularly regards the chronological succession and duration of the activation phases, the specified type of graphic display is superior to, for example, a tabular presentation. The clear presentation of much information is thus possible in the case of the inventive apparatus without the risk of mis-operations. An operator is thus provided with additional certainty that the apparatus is in fact activated in the way intended by the operator.
To avoid incorrect operations, in an embodiment of the invention, the control unit implements a check of the permissibility of the values that have been set with respect to the pre-selected value of the operating parameter and/or the duration of the activation phase and/or the time intervals between successive activation phases and inhibits the enable means if an inadmissible value is pre-selected. In this context, an identification of inadmissible values can ensue on the display means, so that an operator can immediately recognize the critical point and provide alleviation. The control unit can determine the allowed value that comes closest to the inadmissible, pre-selected value and cause this value to be displayed on the display means. Inadmissible values thus can be identified by the control unit on the basis of a model of the apparatus stored in the control unit. Alternatively, the control unit can determine the admissible values coming closest to an inadmissible pre-selected values by simulation calculation.
In a further embodiment of the invention, at least one further operating parameter can be displayed on the display means that takes effect during at least a part of the activation phases with a pre-selectable value, with the further operating parameter with illustrated as a stripe within the rectangle representing an activation phase within which the further operating parameter takes effect, and the width of the stripe in the direction of the time axis corresponding to the pre-selected value of the further operating parameter.
The apparatus is preferably a medical apparatus and, in particular, an apparatus containing an X-ray tube, preferably a computer tomography (CT) apparatus or an X-ray angiography apparatus, wherein the tube current or the mAs product can be set as the operating parameter, the duration of the X-radiation can be set as the duration of the activation phase, and the waiting time between successive exposures can be set as time interval between successive activation phases.